The visitors had both goalkeeper Richard Strebinger and full-back Patrick Farkas sent off and the hosts took advantage with goals from Jonjo Shelvey, Josh McEachran, Marvin Sordell and Connor Wickham.
That gave England U21 a ninth successive win - following on from Thursday's 3-0 defeat of Romania - and sent Pearce home happy ahead of this summer's European Championship.
He said: "This last eight-day block we've had, I certainly could not have asked for more in terms of results.
"I think the result tonight flattered us a bit. It was nicely balanced, with chances at both ends and some good defending at the beginning.
"The sending off, certainly the second sending off, slanted the game a little bit and probably we didn't learn a great deal after that, to be honest with you.
"But the two-game exercise for has been absolutely invaluable in regards to shaping my mentality for the squad this summer.
"The boys have been outstanding, as they normally are, over these eight days at the hotel, on the training ground and on the match pitch.
"There are lessons to be learned but I think they have the mentality to get better. We've got bigger challenges in the summer.
"Our scouts have been looking at the Italians, Norwegians, Spanish - there are some good sides coming to this championships.
"We won't get washed away with thinking just because we won a couple of games on the spin that it is going to be nice and comfortable in the summer. It will be anything but."
Pearce is planning to name his 23-man squad for the European Championship in the week starting May 13 and has eyes on the likes of Alex Oxlade-Chamberlain, Kyle Walker and Jack Rodwell, as well as the U21 regulars.
"If everyone was fully fit then I would say in the region of 20 or 21 people I know in my mind I would choose," he said.
"I still feel there is an opportunity for individuals that maybe haven't been consistently around the squad to stake a claim between now and the summer.
"Then obviously you're down to form and fitness so it is quite fluid the Under-21s.
"Saying that, we have had some real consistent performers in the Jordan Hendersons, Craig Dawsons and the Jack Butlands which have carried us through."